Preparation and characterization of a metal-rich activated carbon from CCA-treated wood for CO2 capture.

The disposal of eucalyptus poles used in the electricity network distribution is considered a potential contamination to the environment due to the chromated copper arsenate (CCA) used as a wood preservative. The thermochemical process can be an alternative to this toxic waste disposal. In this work, the slow pyrolysis of CCA-treated wood followed by the production and application of activated carbon was proposed. Metal retention (ICP-OES), concentration of non-condensable gases produced in the pyrolysis process (via GC), as well as the capacity of activated carbon on CO 2 adsorption (via TGA) were investigated. The highest formation rate of non-condensable gases was observed at 500 °C, while the maximum H 2 concentration was at 700 °C. The char obtained in the pyrolysis was chemically treated with H 3 PO 4 and activated in CO 2 flow. The pore size distribution of activated carbons showed pore sizes lower than 1 nm. The activated carbons showed a CO 2 adsorption capacity of 70–83 mg/g. The presence of chromium and copper may have influenced the CO 2 adsorption. The fast adsorption and desorption showed by the activated carbon produced from CCA-treated wood is interesting to systems that operate in short-time cycles, as pressure swing adsorption (PSA). The reuse of CCA-treated wood for activated carbon production and its application in the CO 2 adsorption could be a solution to minimize the environmental damage caused by this waste. [ABSTRACT FROM AUTHOR]